"As a result of the attack on a police post and a local sauna on the outskirts of the town of Buinaksk, 11 people were killed, including four policemen and seven sauna employees," RIA Novosti reported.

Earlier, a local police spokesman was quoted by Interfax as saying that the assailants fled the scene.

There were at least three other incidents in Dagestan on Thursday.

In separate incidents in Dagestan's capital Makhachkala, a police car came under fire and two policemen were wounded by an unknown attacker, police said, adding that the same sniper could have been to blame for both incidents.

An explosive device was also found near a railway close to Makhachkala, officials quoted by RIA Novosti said, forcing police to block off the road.

Concerns have mounted over increased militant attacks throughout Russia's Caucasus region, where Islamist militants have been battling pro-Kremlin local authorities and Russian security forces in a low-level insurgency.

Dagestan is of particular concern after militants in June shot dead the region's long-serving interior minister as he was attending wedding celebrations for a colleague's daughter.